Project HookMeUp Atlanta Area In Home Help

Moving into new home with existing Nortek GC2 security unit but can't access it. Codes not available and or changed. Need a rouge installer that knows his/her @#$%^&*(...someone who understands how to rest installer and master codes and integrate my desired features with existing GC2 Unit IF possible. Previous alarm company either locked out installer code or not sure but system is pristine shape with 6-7 contacts. Desire Iwatch monitoring functionality and Nest Door Bell/Camera whether stand alone or integrated. System is installed just need it all working for at least self monitoring if not more. Likely Needs batteries. System has been disconnected for 2 years. My guess is 4-5 hours of work, maybe more.